im working in hongkong and i want my sons and parents to come here for a visit what they need to do

Philippines passport holders can stay in Hong Kong for up to 14 days. So if they'll stay for less then 14 days, they don't need to apply for a HK visa. Just assure their passport will be valid for at least 44 days on the arrival day.

If they are going to stay for more than 14 days, they then need to apply for HK tourist visas from China embassy in Philippines. The requirements include:
Forms and Documents to be Submitted by the Applicants
1. Application for Entry for Visit/Transit in Hong Kong (ID 1003A)
2. The applicant's recent photograph (affixed on page 1 of the application form ID 1003A)
3. Photocopy of the applicant's travel document containing personal particulars, date of issue, date of expiry and/or details of any re-entry visa held (if applicable)
4. Photocopy of proof of the applicant's financial standing, e.g. bank statements, savings accounts passbooks, tax receipts, etc.
5. Photocopy of proof of transportation arrangement, e.g. flight itinerary
6. Photocopy of proof of the proposed business visit to Hong Kong, e.g. letter issued by a trade body to confirm the applicant's attendance at trade fairs and exhibitions, etc. (for business visit only)
7. Other deemed necessary requirements by the embassy.

Forms and Documents to be Submitted by the Sponsor
(i) For application in which the sponsor is a Company:
1. Application for Entry for Visit/Transit (Sponsor) in Hong Kong (ID 1003B)
2. Photocopy of Business Registration Certificate

(ii) For application in which the sponsor is an Individual:
1. Application for Entry for Visit/Transit (Sponsor) in Hong Kong (ID 1003B)
2. Photocopy of the sponsor's Hong Kong identity card
3. Photocopy of the sponsor's travel document containing personal particulars, date of issue, date of expiry, and the latest arrival stamp/extension of stay label in the HKSAR (for non-permanent resident of the HKSAR only)